Detergent solutions from parts washers, quenching baths, machine tools, and the like are contaminated with solids such as dirt, grit, scale and metal cuttings and with liquids such as tramp oil, and the like. Oil-laden solution emulsions are formed and it would be a considerable saving in energy and manufacturing costs if the solutions could be cleaned, freed of the tramp oil, and continuously recycled while at the same time recovering the oil constituent for re-use. It would be an improvement in the art to provide an inexpensive circulating system having a compact unit operated with a minimum energy input which will service parts washers, aqueous coolant and lubricant systems, quenching tanks, and the like industrial equipment to maintain the cleaning, cooling, or other solutions in a condition freed from contaminants and oil while at the same time recovering the oil for re-use. It would be a further improvement in the art, to provide an aqueous solution recovery system which maintains the integrity of the solutions, requires no added chemicals, no heat or cooling input, and is pre-piped for continuous recycling so that no altering or modification of the industrial equipment being serviced is needed.